The present invention relates to a balloon catheter which may be used to deliver and deploy a stent in a blood vessel. More particularly, the invention relates to a segmented balloon catheter which may be used to deploy one or more stents in a bifurcation of the blood vessel in order to treat an occlusion or lesion occurring in or near the bifurcation.
Balloon catheters are commonly used to treat certain conditions of a blood vessel, such as a partial or total occlusion or lesion of the vessel which may be caused by, for example, atherosclerotic plagues or thrombosis. In an angioplasty procedure, the balloon portion of the catheter is advanced over a guide wire to the site of the occlusion and inflated to compress the occlusion and thereby restore normal blood flow through the vessel. In some instances, a stent may be implanted in the blood vessel to prevent the occlusion from recurring. A balloon catheter is commonly used to deliver and deploy the stent in such a stenting or stent implantation procedure. The stent is typically mounted in its unexpanded state on the balloon portion of the catheter, delivered to the site of the occlusion and then deployed or implanted in the vessel by inflating the balloon portion.
Prior art stenting procedures often are unsuitable for treating a condition of a blood vessel occurring at or near a bifurcation of the blood vessel, that is, the intersection of a main vessel with a side branch vessel. One method for stenting an occlusion in a bifurcation involves implanting a first stent in the main vessel adjacent the bifurcation and then implanting a second stent in the side branch vessel adjacent the bifurcation (the so-called xe2x80x9cT-stentingxe2x80x9d procedure). However, this requires that the guide wire for the balloon catheter which is used to deliver the second stent be threaded through the struts of the first stent and into the side branch vessel. This process can be quite difficult and time consuming. Furthermore, the stenting of the main vessel may shift plagues and thereby close off the side branch vessel, making it extremely difficult to insert the guide wire into the side branch vessel.
Also, prior to stenting, the occlusion is commonly pre-dilated using a balloon angioplasty procedure. In preparation for a balloon angioplasty procedure in a bifurcation, a first guide wire is inserted into the main vessel and a second guide wire is inserted into the side branch vessel. Thus, even if shifting plagues should close off the side branch vessel during dilation of the main vessel, the side branch vessel can still be approached via the second guide wire. However, in prior art stenting procedures for occlusions in bifurcations, the second guide wire must usually be withdrawn from the side branch vessel prior to stenting the main vessel so that it will not interfere with the deployment of the stent in the main vessel. Consequently, difficulty may be experienced in inserting the second guide wire back into the side branch vessel prior to stenting or otherwise re-treating the side branch vessel.
In accordance with the present invention, these and other disadvantages in the prior art are addressed by providing a segmented balloon catheter for use in treating a condition of a vessel occurring near a bifurcation that is defined by the intersection of a main vessel with a side branch vessel. The segmented balloon catheter comprises a shaft which includes a proximal end, a distal end and a longitudinal passageway that extends therethrough from the proximal end to the distal end; a first balloon portion which is mounted on the shaft adjacent the distal end; and a second balloon portion which is mounted on the shaft adjacent the first balloon portion. The shaft also comprises a transverse port which extends between the longitudinal passageway and the exterior of the segmented balloon catheter from between the first and second balloon portions. A proximal end of a first guide wire which is pre-positioned in the main vessel may be inserted into the distal end of the shaft and threaded through the longitudinal passageway and out the proximal end of the shaft. In addition, a proximal end of a second guide wire which is pre-positioned in the side branch vessel may be inserted into the transverse port and threaded through the longitudinal passageway and out the proximal end of the shaft. In this manner, the first and second balloon portions may be guided to the bifurcation on the first and second guide wires.
In accordance with one embodiment of the invention, the segmented balloon catheter also comprises a stent which is mounted on the first and second balloon portions. In addition, the stent may comprise a window which is aligned with the transverse port in the shaft and through which the second guide wire extends. In this manner, the segmented balloon catheter may be used to deliver and deploy the stent in the main vessel adjacent the bifurcation. Furthermore, a second balloon catheter may then be threaded onto the second guide wire and used to deliver a second stent through the window and into the side branch vessel adjacent the bifurcation.
Thus, the segmented balloon catheter of the present invention provides a simple and efficient means for treating a condition of a blood vessel occurring at or near a bifurcation of the blood vessel. Since the segmented balloon catheter requires the pre-positioning of the first and second guide wires in the main and side branch vessels, respectively, the second guide wire can remain in place in the side branch vessel after a pre-dilation procedure, thereby eliminating the need to withdraw the second guide wire prior to stenting the main vessel. Also, since the second guide wire is threaded through the lateral port between the first and second balloon portions, the second guide wire will guide the placement of the first and second balloon portions across the opening to the side branch vessel. In addition, because the second guide wire is threaded through the stent before the stent is introduced into the vessel, the second guide wire may remain in position while the stent is deployed in the main vessel, thereby eliminating the need to thread the second guide wire through the stent after the stent is deployed in the main vessel. Furthermore, since a second stent may be deployed in the side branch vessel on the second guide wire, the first guide wire may remain in the main vessel during the stenting of the side branch vessel in the event the main vessel requires a subsequent treatment.
These and other objects and advantages of the present invention will be made apparent from the following detailed description, with reference to the accompanying drawings. In the drawings, the same reference numbers are used to denote similar elements in the various embodiments.